Quantitative monitoring of personal exposure to environmental toxins is currently limited by expense, inconvenience and lack of appropriate technology, yet such monitoring is needed for investigation of health effects caused by low dose, chronic exposure to compounds such as pesticides or industrial toxins. We have previously demonstrated that low concentrations of a semi-volatile organophosphate pesticide can be detected from a vapor phase by utilizing chemically functionalized, nanostructured surfaces and liquid crystals (Platypus( technology). What is needed, however, is a monitor that simultaneously measures exposure to multiple compounds. In this proposal, we will demonstrate the feasibility of developing Platypus( technology for the quantitative and simultaneous detection of two different classes of semi-volatile pesticides (carbamates and organophosphates) and for the discrimination of specific compounds within each class of pesticide. The technology developed in this project can be adapted for detection of other industrial or environmental contaminants that are semi-volatile, and thus it has the potential to serve as the basis for a broadly useful, convenient and inexpensive class of passive monitors for multi-compound personal exposure assessment and environmental monitoring. In this proposal, we are developing a small, inexpensive wearable device which will provide a measurement of an individual's exposure to multiple chemicals present in his or her environment over a period of a day to a few weeks. This data is essential for associating exposure to specific compounds with adverse affects on public health. [unreadable] [unreadable] [unreadable]